UVA influenced the SIRT1-miR-27a-5p-SMAD2-MMP1/COL1/BCL2 axis in human skin primary fibroblasts.

Both SIRT1 and UVA radiation are involved in cellular damage processes such as apoptosis, senescence and ageing. MicroRNAs (miRNAs) have been reported to be closely related to UV radiation, as well as to SIRT1. In this study, we investigated the connections among SIRT1, UVA and miRNA in human skin primary fibroblasts. Our results showed that UVA altered the protein level of SIRT1 in a time point-dependent manner. Using miRNA microarray, bioinformatics analysis, we found that knocking down SIRT1 could cause up-regulation of miR-27a-5p and the latter could down-regulate SMAD2, and these results were verified by qRT-PCR or Western blot. Furthermore, UVA radiation (5 J/cm2 ), knocking down SIRT1 or overexpression of miR-27a-5p led to increased expression of MMP1, and decreased expressions of COL1 and BCL2. We also found additive impacts on MMP1, COL1 and BCL2 under the combination of UVA radiation + Sirtinol (SIRT1 inhibitor), or UVA radiation + miR-27a-5p mimic. SIRT1 activator resveratrol could reverse damage changes caused by UVA radiation. Besides, absent of SIRT1 or overexpression of miR-27a-5p increased cell apoptosis and induced cell arrest in G2/M phase. Taken together, these results demonstrated that UVA could influence a novel SIRT1-miR-27a-5p-SMAD2-MMP1/COL1/BCL2 axis in skin primary fibroblasts, and may provide potential therapeutic targets for UVA-induced skin damage.

[Effects of complement inhibiting component of Ephedra sinica on immunological inflammation following acute spinal cord injury in rats].

OBJECTIVE: To investigate the effects of complement inhibiting component of Ephedra sinica on immunological inflammation following acute spinal cord injury (SCI) in rats. METHODS: The complement inhibiting component of Ephedra sinica was isolated by multiple precipitation steps and thin layer chromatography, and then the activity was analyzed. Fifty healthy SD rats were selected and randomly divided into the control group and the experimental group, 25 in each group. Induction of SCI was performed following a modified Allen's weight-drop method. The complement inhibiting component from Ephedra sinica (15 mg/kg) dissolving in 5 mL normal saline was immediately administered by gastrogavage after SCI, once daily. Equal volume of normal saline was administered to rats in the control group by gastrogavage. Hematoxylin and eosin (H&E) staining and C3 immunohistochemical staining were performed in SCI tissue at 12 h, day 1, 3, 7, and 14 after SCI. C3 positive expressions and myeloperoxidase (MPO) activity were assessed. Intercellular adhesion molecule-1 (ICAM-1) mRNA expression level was evaluated by Real-time PCR technique. RESULTS: C3 positive expression, MPO activity, and ICAM-1 mRNA level were significantly weaker in the Ephedra sinica group than in the control group at all time points (12 h, day 1, day 3, day 7, and day 14 after SCI) (P < 0.01, P < 0.05). CONCLUSIONS: There existed complement system activation following acute SCI. The complement inhibiting component of Ephedra sinica significantly reduced immunological inflammation after SCI, and played an important role in secondary SCI.

Effects of recombinant sCR1 on the immune inflammatory reaction in acute spinal cord injury tissue of rats.

OBJECTIVE: To determine the effects of recombinant soluble complement receptor type I (sCR1) on the immune inflammatory reaction in acute spinal cord injury tissue of rats and its protective effects. METHODS: SD rat models of acute spinal cord injury were prepared by modified Allen's method. The motor function of the rat lower extremities in sCR1 group and normal saline (NS) group was evaluated by the tiltboard experiment at 12 h, 1 d, 3 d, 7 d, and 14 d. The neutrophil infiltration and C3c positive expression were observed. The myeloperoxidase activity was assessed in the injury tissue at 12 h, 1 d, 3 d, 7 d, and 14 d after injury in the two groups. RESULTS: The motor function of rat in sCR1 group at 3 d, 7 d, and 14 d was obviously better than that in NS group (P<0.01, P<0.01, P<0.01). C3c positive expression in sCR1 group at each time point after injury was obviously less than that in NS group (P<0.01). The myeloperoxidase activity in sCR1 group at each time point after injury was obviously less than that in NS group (P<0.01). CONCLUSIONS: Recombinant soluble complement receptor type I (sCR1) can lessen the immune inflammatory reaction in acute spinal cord injury tissue and relieve secondary spinal cord injury by inhibiting the activation of the complement system.